Render Layers are not visible in compositing when I close and open the program
No, blender does not save the rendered layers as part of the project.

You need to render them again, or you can save them as an image first and import them back into blender for compositing.

To keep the best quality use a "output file node" and save as EXR multilayer. Read: Save all render passes to a single EXR image and Different render per layers? and How can I render all render passes to files in Cycles?